KEY MOMENT - WHEN HE SAYS 'YES!'
"The key moment to the coronation is not the most glamorous moment or the most bling moment. It's the moment when he accepts. He says, 'I vow to uphold the Church of England and the Constitution. This is the kind of king I'm going to be. I'm going to do the job right'," royal historian, Professor Kate Williams told Reuters.
CROWNING - THE BIG PHOTO MOMENT
The moment everyone will be talking about though, said Williams, is when Charles is crowned.
Sitting on a coronation chair dating back more than 700 years, Charles is given regalia, from bejewelled orbs and sceptres to swords and a ring.
The culmination sees the 360-year-old St Edward's Crown, weighing in at 2.2 kg (4 lb 12 ounces) and a replacement for an original dating back to the 11th Century, placed onto Charles' head by the Archbishop of Canterbury.
"The big moment, the big photograph moment, the big moment that everyone's going to be talking about, making memes of, making TikToks of, that's when the king is crowned when the king has the crown put on his head," said Williams.
"People often focus on this moment of crowning because symbolically, that's the sort of moment where they (the king or queen) have been given this regalia. They've been given the outward symbols of monarchy,'' said Charles Farris, Public Historian At Historic Royal Palaces.
Although constitutionally Charles has been king since the death of Queen Elizabeth II, Farris said the gesture of a crown going on, is an "important moment for many people, including people watching."
ANOINTING - THE MOST SACRED PART
During the service, Charles will be anointed with holy Chrism oil, made using olives from the Mount of Olives and consecrated in Jerusalem.
The tradition of dates back to the Old Testament of the Bible which describes the anointing of King Solomon by Zadok the Priest and Nathan the Prophet, and has been maintained to emphasise the spiritual status of the monarch.
"This is often thought to be the most sacred part of the ceremony," said Farris. "It's an ancient and very symbolic ceremony...historically it was akin to the anointing of priests and bishops.
"It's a way of the church cementing their relationship with the new monarch but also a clear symbol to all present that the monarch has been marked out as very special."
CAMILLA WILL BE CROWNED
Charles' wife Camilla, Queen Consort will also be crowned queen during the ceremony, a tradition Williams said dates to Eleanor of Aquitaine who was the queen of France and then England in the twelfth century.
"We have an interesting anomaly...queens, their husbands are not part of the ceremony...but the tradition is that you are crowned with your spouse if you are a king. So, therefore, we will see Camilla crowned,'' said Williams.
"She has her crown - Queen Mary's crown that Queen Mary commissioned for her coronation in 1911...Camilla is also anointed."
DON'T FORGET THE MUSIC AND THE COACHES
The ceremony will feature twelve new works, which Charles commissioned or selected, including a new coronation anthem by musical theatre impresario Andrew Lloyd Webber.
Along with the new, there will be the usual trumpet fanfare and music which has been historically used at coronations over the last four centuries.
A grand procession by the royals in historic coaches through central London is always a highlight of any major state occasion.
Charles and his wife Camilla will break with tradition and travel from Buckingham Palace to London's Westminster Abbey in the modern Diamond Jubilee State Coach, made to commemorate his mother's 60th year on the throne.
They will return from the Abbey in the Coronation Procession in the 260-year-old Gold State Coach which weighs four tonnes and needs to be pulled by eight horses. It has been used at every coronation since King William IV's in 1831 and was first used by George III to travel to the State Opening of Parliament in 1762.
AND FINALLY, THE BALCONY SCENE
Having returned to Buckingham Palace, the big finale - as it is for weddings, jubilees and other major royal events - is the appearance by the senior Windsors on the balcony at Buckingham Palace.
There will be a flypast by military aircraft including the Red Arrows Royal Air Force aerobatic team and historic planes from World War Two.
While the newly-crowned king and queen will be the centre of attention, all eyes will be on whether Charles' younger son Prince Harry appears.
But, people will also be watching Prince Louis, the youngest child of heir Prince William, who stole the show last year during celebrations for Queen Elizabeth's Platinum Jubilee by covering his ears amid the din caused by a flypast.
REFLECTION ON THE WHOLE CORONATION
Reflecting on the significance of seeing a coronation, the first since Queen Elizabeth II's in 1953, Farris said it is "incredibly exciting".
"I've been reading about royal history for many years now...it's a privilege to see these objects in action, the crown jewels, and to see one of these events which have been so important for hundreds, even thousands of years in our history. To see one unfold is going to be exciting," he said.
Reuters